What is this feature?

Nope, no negatives, and I don't believe there is an official name for it.  It is a nice feature, right next to a time delay when powering up a power amp and getting a huge thump in your subs.

When I turn my linestage off, the motorized pot automatically goes back to full off position.   If one wanted to preserve the precise listening level of the last session, this would be a negative, but, apart from that, I don't see a real problem.  I like the assurance that I will not be accidentally blasting the system.

The Alchemist integrated designed by Tim deParavincini when powered on the volume would go to zero before the relay would trip. Never cared for this feature myself. 

I don't know the name of the feature, but I've encountered it in two different versions. When my Classe CAP-101 powered up, the volume would reset to zero and a 10-second countdown ensued before it could be increased. With the Wyred4Sound STI500-II, if the last volume used before powering down is at or below level "29," the volume starts at that level upon powering up. If the last volume is "30" or more, then the volume starts at level "23," a moderate level. I prefer Wyred's approach but never minded Classe's, thanks to having a remote so I didn't have to stand in front of the amp waiting to set the volume.